Process of smelting lead-sulfid ores.



UNITED stares ent ies.

ANSON GARDNER BETTS, F THGY, NEW YORlQ PFIDCESS or sunscreen tene ents-in ones. i

Specification of Letters Patent.

, PatentedMay 22, 1906.

Application filed May 20, 1904. Serial No. 208,9*l6.

To -all whom it may concern:

Be it known that I, Anson GARDNER ing at Troy,-county of Rensselaer, and State ofNew York, have invented certain new anduseful Improvements in Processes of Smelting Sulfid Lead Ores, of which the following is a specification.

TlllS invention relates to a recess of desuls furizing galena by the com ined action of carbon or carbon compounds and iron oxide with or without the assistance of basic sodium com ounds, but always in presence of sosu fid or of substances y1elding sodium sulfid.

The principal object of my invention is to.

smelt lead ore without requiring the admixture of silicious ores and to reduce the losses of lead in smelting.

To carry out my invention in its preferred form, I prepare a smelting charge consisting of approximately sixty-jive parts lead sulfid, twentyparts siderite or limonite or the equiv-v alent amount of other iron oxide free from or containin Water, twenty parts sodium carbonate, w ch may be in part replaced by the equivalent amount of caustic soda, and twelve to fifteen parts fine coal or coke. In general the mixture will contain some silica, blende, pyrite, limestone, or other gangue of the lead-sulfid ore. v

The rincipal reactions which take place when t e mixture is heated are The mixture is preferably smelted in an ordinary reverberatory smelting-furnace.

The fusion takes place at a moderate temperature, yielding nearly all'the lead ofthe ore as metal and an easily-fusible iron-sodium matte.

Loss by volatilization of lead scarcely takes place at all when the charge is covered with a little coalor the flame in the furnace is reducing, I having observed that lead is only volatilized when oxidizing-gases come 1n contact with the charge. The mixture can be smelted m a blast-furnace, which should be run so that there 1s an excess of carbon monoxid in the escaping gase.s Success is attained by proportioning the furnace charge so that the matte produced contains considerable proportions of both iron sulfid and sodium sulfid, for the reason that the mixed sulfide melt at a comparatively low temperature and themixture does not hold in igneous solution appreciable uantities of metallic iron or lead, which is t e case With iron sulfid alone. Sodium sulfid alone is diflicultly fusible. The matte,

. leaving out of consideration silica, zinc, &c.,

best approximates in composition the formula N a S.FeS. As iron is a cheaper agent than soda, it is usually more economical to use more iron and less sodium than this formula requires. Iron ores containing manganese are equallyas good as pure iron ores, as manganese acts analogously to. iron.

When sodium sulfate or sodium sulfid are available at a low price, I can replace sodium carbonate as desulfurizer with. iron oxid and add enough sodium sulfate or sulfid to reduce the percentage of iron sulfid in the matte to a desirable" figure. When sodium sulfate is used, this reaction occurs:

Pyrite mixed with the galena can be figured as yielding sulfur and ferrous sulfid, Which latter forms part of the matte.

Lead oxid if present in raw or roasted ore is directly reduced by carbon and takes no. part in the formation of matte. Lead sulfate, if present, should be allowed for by allowing enough carbon to reduce it to lead sul fid, and then the lead sulfid produced should.

' be figured as so much galena.

When I have specified iron in the claims, it is to be understood that iron is replaceable by manganese. It is also to be understood that sodium carbonate containing sodium hydroxid is available as sodium carbonate, for the result is the same.

What I claim as new, and desire to secure by Letters Patent, is-

'1. The process of reducinglead sulfid which consists in smelting it with a carbon-reducing agent, iron oxid, and a suitable oxygenated sodium compound, in proportions to produce metallic lead, and an iron-sodium matte, as set forth.

2. The process of reducinglead sulfid which consists in smelting it, with a carbon-reduc ing agent, and basic compounds of iron and sodium, in proportions to produce metallic lead, and an iron-sodium matte, as set forth.

. 3. The process of reducinglead sulfid which consists in smelting it by radiated heat with carbon and basic compounds of iron and sodium in proportions to produce metallic lead, and a fusible iron-sodium matte, as set forth.

IIO

'4; The process of reducing galena which I mately the proportion given by the formula consists in smelting it with carbon, iron ,Xid .Na'-S.FeS. and a basic sodium compound, to produce In testimony whereof I have signed my metallic lead, 'and a fusible iron-sodium name to this specification in the presence of 5 matte, as set forth.

- 5.' The process of reducing lead sulfid which i consists in smelting it With carbon, iron oXid i and sodium carbonate, to produce metallic lead and an iron-sodium matte in which iron 1.0 and sodium sulfids are present in approxitwo subscribing Witnesses.

ANSON GARDNER BETTS.

Witnesses:

EDWARD F. KERN, WILLIAM VALENTINE. 

